A conventional fluid pressure control device shown in FIG. 48 includes a body 1 having a fluid channel through which brake fluid flows. As shown in FIG. 48, solenoid valves 2 for opening and closing a fluid channel are mounted on the body 1. The case 3 is formed by connecting a solenoid housing 32 and a connector housing 33 at a connecting portion 1A. The solenoid valves 2 respectively include solenoids 21 which are located in a solenoid chamber 2A formed by the solenoid housing 32.
A resin cover 3A is attached to the case 3 and forms a board chamber 4A. The board chamber 4A and the solenoid chamber 2A are separated from each other by a partitioning wall 5A of the case 3. A board 5 is located in the board chamber 4A and is supported by board holding members 6A of the case 3.
Solenoid terminals 22 of the solenoid valves 2 extends from the solenoid chamber 2A to the board chamber 4A, penetrating the partitioning wall 5A. The solenoid terminals 22 are accordingly connected with the board 5 by soldering. Ends of the connector terminals 4 formed by insert molding are attached to the board 5.
The case 3 and the cover 3A are welded together at an open end of the cover 3A. Seal members are inserted to portions of the partitioning walls which the solenoid terminals 22 penetrate. Thus, airtightness of the board chamber 4A is attained. A contacting surface between the body 1 and the case 3 are sealed by a packing 35 (See JP 2002-368452A).
In the above described fluid pressure control device, the solenoids 21 are fixed to the body 1 by caulking. However, another conventional fluid pressure control device is known in which the solenoids 21 are not fixed to the body 1. In such a fluid pressure control device, as shown in FIG. 49, the solenoids 21 are pushed by springs (waved washers) 7A located between the solenoid 21 and the body 1 and are accordingly pressed against stoppers 8A formed at the case 3. Thus, the solenoids 21 are properly positioned by the springs 7A and the stoppers 8A. Therefore, the solenoids 21 can be moved apart along with the case 3 from the body 1 when bolts fixing the case 3 to the body 1 are removed.
However, each of the conventional fluid pressure control devices includes the solenoid chamber 2A and board chamber 4A separately, and the partitioning wall 5A and the cover 3A are therefore necessary. This causes raise in manufacturing cost of the fluid pressure control device. The mount of the raise increases as the size of the fluid pressure control device increases.
In addition, a large amount of portions which need sealing causes rise in risk to the reliability of sealing of the fluid pressure control device as well as rise in the manufacturing cost of the fluid pressure control device.
In addition, in the conventional fluid pressure control device in which the solenoids 21 are fixed to the body 1 by caulking, the solenoids 21 are supported by members different from those for supporting the board 5. Besides, the board 5 is supported by the case 3, which has a linear coefficient of expansion larger than that of the body 1 supporting the solenoids 21. Therefore, heat load causes a difference in an amount of expansion between the case 3 and the body 1, which likely results in stresses causing solder cracking at connecting portions at which the solenoid terminals 22 are connected with the board 5 by soldering.
On the other hand, in the conventional fluid pressure control device in which the solenoids 21 are positioned by the stoppers 8A of the case 3, thermal expansion of the board holding portion 6A, the partitioning wall 5A, and the stoppers 8A under heat load increases distances from the solenoids 21 to the board 5. Therefore, stresses are generated at the connecting portions between the solenoid terminals 22 and the board 5, and solder cracking accordingly becomes likely to occur.